title: The differential detection of methicillin-resistant, methicillin-susceptible and borderline oxacillin-resistant Staphylococcus aureus by surface plasmon resonance.
abstract: Two hundred fifty Staphylococcus aureus clinical isolates were studied to determine their susceptibilities to β-lactam antibiotics. Among these isolates, 16 were methicillin-sensitive S. aureus (MSSA), 207 were methicillin-resistant S. aureus (MRSA) and 27 were borderline oxacillin-resistant S. aureus (BORSA). Currently, the reported mechanism of methicillin resistance in S. aureus is the production of a distinctive penicillin binding protein 2a (PBP2a), which exhibits low affinity toward β-lactams. A surface plasmon resonance biosensor was evaluated for its ability to identify MRSA and to distinguish these strains from MSSA and BORSA, by specifically detecting PBP2a. We found that the system permits label-free, real-time, specific detection of pathogens for concentrations as low as 10 colony forming units/milliliter (CFU/ml), in less than 20 min. This system promises to become a diagnostic tool for bacteria that cause major public concern in clinical settings.
authors.affiliation: Laboratory for the Analysis of Surfaces of Materials, Department of Engineering Physics, École Polytechnique de Montreal, Case Postale 6079, succursale Centre-Ville, Montreal, Québec H3C 3A7, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Tawil
authors.forename: Flaviana
authors.initials: F
authors.lastname: Mouawad
authors.forename: Simon
authors.initials: S
authors.lastname: Lévesque
authors.forename: Edward
authors.initials: E
authors.lastname: Sacher
authors.forename: Rosemonde
authors.initials: R
authors.lastname: Mandeville
authors.forename: Michel
authors.initials: M
authors.lastname: Meunier
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis; D024881:Drug Resistance, Bacterial; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D010068:Oxacillin / Q000494:pharmacology*; D046915:Penicillin-Binding Proteins / Q000032:analysis; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; D010068:Oxacillin
keywords: Biosensor; Borderline oxacillin-resistant Staphylococcus aureus (BORSA); Methicillin-resistant Staphylococcus aureus (MRSA); Methicillin-sensitive Staphylococcus aureus (MSSA); Penicillin-binding protein (PBP); Surface plasmon resonance (SPR)